Application of multi-block CFD techniques to a missile geometry

Abstract

The aerodynamics of a missile body were modeled using computational fluid dynamics (CFD) techniques. A multi-block approach was used on a slender body and intersecting symmetric thin delta-wing. The CFD process and software were examined thoroughly including multi-block grid generation and interpolation, iblanking methods and flow-solver analysis. CFD results were compared with available wind tunnel data. Two Cartesian free-stream grids, a wing C-grid, a collar and body grid were used to model the body/wing geometry. The wing grid had a sharp tip and sharp leading and trailing edges. The body/wing intersection was represented with the collar grid. Both a hyperbolic grid generator, HYPGEN and an elliptic grid generator, GRIDGEN Vr 9, were evaluated. PEGSUS Vr 4.0 was used to compute the iblanking and interpolation stencil, based on the Chimera overlapping grid scheme. A single composite mesh was passed to the Navier-Stokes implicit flow-solver OVERFLOW Vr 1.6ag. Solutions were computed for inviscid and viscous flows at different Mach numbers and incidence angles. The Baldwin-Lomax shear and boundary layer turbulent models were used. Agreement was found between published wind tunnel data and the CFD solution thus validating the grid generation and flowfield solution procedure.